Wednesday

There are two basic types of air-con units in Japan: wall mounted and window mounted (let's ignore the industrial ceiling-mounts for now). Each has it's pros and cons which will be discussed in the next couple of weeks. For now, let's look at the factors which determine if a unit retails for the low end (30,000 yen and up) or the high end (120,000++).Capacity

As Japanese rooms are usually measured in units of tatami mats, AC is graded in the same way. Look for the 畳 (jou, also the kanji for tatami) kanji. 5-7畳 means the unit is suitable for a room between 5 and 8 mats in size (8-12 metres squared). Bigger than this and it will still work, but be prepared for a reduction in efficacy.

Heater function (暖房 - danbou)
Many air-con units can double as a heater in the winter.

Dehumidifier (ドライ - dorai)
Can be used alone (without cooling or warming the air), and is quite useful when it's not quite hot enough for AC, but very humid.

Oscillation (オートスイング - ooto suingu)
Lower-end models don't have a rotating blade, so cold air just pumps out in a set (usually set-able) direction. Oscillation is a little more efficient.

Ioniser (usually just "Ion" in English, but sometimes イオンフィルター - ion firutaa)
A feature to purify the air by electronically charging the particles within it. This is something you'd want if you smoke indoors, or have something else releasing potentially harmful or air-degrading fumes (incense or a bad diet or something).

Self-cleaning (セルフクリーニング - serufu kuriiningu)
When AC is turned off, the coil inside responsible for the cold temperature being pumped out is wet. If it isn't dried, mold will form over time and it'll need to be cleaned. A self-cleaning AC will dry the coil automatically when turned off.

Non-drain (ノンドレン - non doren)
No liquid runoff.

As for where to buy, I'd suggest Amazon or Rakuten, before any "real" shops.

That's that. If you know of any functions I missed, let us know in the comments field below. Check back next Wednesday for an explanation of, and guide to installing, window-mounted air-con (窓用エアコン).

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